GHC compiles haskell through about a million different IRs and abstract machines, until eventually reaching Cmm, which is effectively a similar idea to LLVM IR (A very simple C ish imperative language). Any benefits to be had, should be fairly straightforward for the GHC folks to use, which should be cool.
I wasn't trying to be critical, it's just significantly more than most languages (With good reason!). This is a good thing, I dream of when we will have
libraries/frameworks for doing these kind of high level program transformations in a modular way a la LLVM.
Just for some more data, Swift is (Possibly still in the process of, but I don't follow swift so they could have finished years ago) moving to a higher level IR, for similar reasons to Rust and Haskell.
